Antibacterial and molluscicidal phenolic acids from Spondias mombin

Spondias mombin L. (Anacardiaceae), used in traditional medicine because of its antimicrobial properties, was found to contain a series of 6-alkenyl-salicylic acids. They were isolated from the ethanolic extract of leaves and stems of Spondias mombin by a combination of chromatographic methods. Their structure was determined by NMR and MS techniques as (17:3), (17:2) and (17:1) pelandjuaic acid [or 6-(8′Z,11′Z,14′Z-heptadecatrienyl)-salicylic acid, 6-(8′Z, 11′Z-heptadecadienyl)-salicylic acid, and 6-(10′Z-heptadecenyl)-salicylic acid, respectively], 6-(12′Z-nonadecenyl)-salicylic acid, and 6-(15′Z-heneicosenyl)-salicylic acid, the two last compounds being new ones. These phenolic acids were shown to have a pronounced antibacterial effect against Bacillus cereus, Streptococcus pyogenes, and Mycobacterium fortuitum (minimal bactericidal concentration in a concentration range of 3-25 µg/ml), and a molluscicidal effect against the snail Biomphalaria glabrata, an intermediate host in the schistosome life cycle. Because of their high molluscicidal activity (LC90 down to 1-3 ppm), these long-chain salicylic acid derivatives may be important tools in the prevention of schistosomiasis.